[Magnetic drug delivery system--adriamycin-carboxymethyl dextran magnetic nanoparticles].

A novel magnetic drug carrier-carboxymethyl dextran magnetic nanoparticles(CMD MNPs) was prepared. Adriamycin (ADR) was coupled with two types of carrier-neutral dextran MNPs and anionic CMD MNPs, by periodate oxidation. The physico-chemical characteristics and the magnetic guidance effects in vitro and in vivo of ADR-CMD MNPs were studied. The distribution profiles of liver and spleen in mice were studied for both ADR-dextran conjugate MNPs and ADR-CMD conjugate MNPs. The results showed ADR-CMD conjugate MNPs possessed superparamagnetism, the mean diameter was 56 nm, the mass magnetic susceptibility was 1.06 x 10(-4) emu.g-1, and the drug loading was 12.4%. The distribution profiles in liver and spleen revealed that conjugation with neutral dextran MNPs, excessive accumulation of loaded ADR was found in liver and spleen after intravenous administration, while conjugation with CMD MNPs gave a markedly lower concentration in these organs, which indicated less uptake of ADR-CMD conjugate MNPs by reticuloendothelial system(RES) and the advantage of delivering loaded drug to sites other than the RES; thus it opens a new perspective for the active delivery of drug.